Windows (in my case Windows 7) has a tool called startup repair that runs if windows can't be booted anymore. It will use the files from the latest restore point to get the system again into a working state. According to the docs, this procedure does not touch any user files, documents and so on.
After my experience what it does is removing any exe files, dlls, drivers and the like that got added to the system since the last system restore point.
however - there's an exception to that - it also removes .AS files. This made me once loos two full days of work and ever since i pay very good attention on always subversioning all .as files
I'd like to know whether anyone of you already encountered this problem and maybe knows why exactly .as files are affected?